Shader "Unlit/WireframeUV"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _FillColor("FillColor", Color) = (1, 1, 1, 1)
       [HDR] _WireColor("WireColor", Color) = (1, 0, 0, 1)
        _WireWidth("WireWidth", Range(0, 1)) = 1
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 100
        AlphaToMask On
        Pass
        {
             Tags { "RenderType" = "TransparentCutout" }
            Blend SrcAlpha OneMinusSrcAlpha
            Cull Off
            CGPROGRAM
       
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;
            fixed4 _FillColor;
            fixed4 _WireColor;
            float _WireWidth;


            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                fixed4 col = tex2D(_MainTex, i.uv);
                fixed2 uv2 = abs(i.uv - fixed2(0.5f, 0.5f));
                float minUV = max(uv2.x, uv2.y);
                col = minUV < 0.5- _WireWidth ? col* _FillColor : _WireColor;
                return col;
            }
            ENDCG
        }
    }
}
